Combination electric motor and compressor



P 12, 1933- J. L. JONES 1,926,444

COMBINATION ELECTRIC MOTOR AND COMPRESSOR Filed July 20, 1929 15 /5 '1' l l l l/ 19%| U LL- L1 r 'awgz'z'x az James L. JEmES INVENTO ATTORNEY Patented Sept. '12, 1933 sites time,

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r-rieri- COM-BENA'IIUN EEECTRIC MOTOR AND COMPRESSOR This invention relates to a combination motor and compressor or pump.

In connection with the operation of pneumatic tools such as chipping hammers, riveters, drills and the like, it is acknowledged that it is preferable to use compressed air as the motive fluid, in lieu of driving such tools by electric motors, in View of the cushioning effect which prevails in the case of hand tools. While pneumatic oper: ation is preferred, electric operation to a great extent has to be resorted to in View of the inaccessibility of pneumatic power. Realizing this condition in the art, it is the main object of my invention to provide a tool of the character described which may be operated by electricity which is used to compress air which directly drives the working parts so that the advantages are attained of using the most available source of power to produce pneumatic operation and accordingly the aforesaid cushioning effect. It is to be understood, however, that the principles of the invention are of broader application than to the tools specifically mentioned as the same may be embodied in pumps, paint or other sprayers, and the like.

in carrying out the main object, it is especially aimed to provide a structure wherein certain motor parts and those constituting the compressor, pump or the like, interact and are common 'to each mechanism constituting the novel unit, to attain maximum compactness, durability, simplicity and maintain the cost of production and upkeep at a minimum.

The more specific objects and advantages will in part be hereinafter pointed out and otherwise become apparent from a consideration of the description following taken in connection with accompanying drawing illustrating one operative embodiment.

In said drawing:

Figure 1 is a central vertical sectional view taken through the improved unit or device constituting my invention and Figure 2 is a cross sectional view taken on the line 22 of Figure 1.

Referring specifically to the drawing wherein like reference characters designate like or corresponding parts, A designates a casing or housing for the various parts constituting the unit of the present invention and may consist of a magnet frame 1 and end bells 2 and 2 suitably rigidly connected together. Said framel is part of an electric motor and carries the field coils 3 thereof. 4 designates the commutator of the electric motor, with which brushes 4 coact, and which commutator is in the usual conducting relation to an armature coil 5 and armature core 6. The motor shaft consists of a hollow cylindrical section 7 and a solid section 8 connected together as by electric welding at 8, such shaft sections being journalled in the end bells 2 and 2, respectively, as at 9' and 9.

Disposed either concentrically or eccentrically within the hollow shaft section 7 is a frustoconical stator 10 having an attaching plate 11 integral therewith which is electrically welded or otherwise attached to the end bell 2".

One or more air intake ports 13 are provided in the bell 2 and air intake ports 14 are provided in the hollow shaft section "I. A helical flight 12 at one edge is fastened rigidly and air tight to the section 7 and at its other edge intimately fits and wipes the conical surface of the stator 10. The smaller end of the stator 10 is nearest the air inlets 1e and hence received air is caused to travel in a spiral or helical path around the cone in a passage which progressively decreases in cross sectional area toward the larger end Where it discharges through ports 15 in the attaching plate 11.

The inner end of hollow shaft section '7 is formed into a steady bearing 16 for a journal 17 at the inner end of stator 10 and the under surface of such hearing has a series of blades 20 preferably radially disposed to assist in draW ing in and compressing air.

A conventional tool or device 18 which is adapted to use the compressed air discharged through ports 15, and a casing 19 for such tool ordevice 18, may have the unit A attached thereto in any suitable manner as suggested in the drawing.

- Presuming operation, energization of the electric motor from any suitable source of power rotates the hollow shaft '7 and associated rotatable parts which rotates blades 20 causing air from the atmosphere to be drawn in through ports 13 and 14 into said shaft section '7 and forced to travel the passage afforded by the flight 12, entering at the larger end of such passage and being compressed as it passes therethrough due to the progressive diminution of said passage in cross-sectional area toward the ports 15, discharging from such ports 15 to the tool 18 or other means for use. Thus it will be seen that the parts so interact that they constitute parts of both a motor and of a compressor or the like.

The invention is not limited to uses as just stated since the principles may otherwise be practised and for instance in a pump or sprayer in which event, the ports 15 would constitute the inlets rather than outlets, and pipes or the like would connect the ports 13 and 14 and such pipes would constitute the outlets.

Various changes may be resorted to within the spirit and scope of the invention and for instance, the fiight 12 may be rigidly secured to stator 10 and wipe the inner wall of shaft section 7, that is, be directly the opposite of the mounting illustrated; the stator 10 could be revoluble and geared to shaft section '7 to be driven thereby but at a different speed; the flight 12 may be made sectional or cast integral with either part I claim as my invention:

1.A device of the class described comprising a motor having a hollow cylinder constituting its shaft, a tapered member therein, one of said parts being rotatable relatively to the other, interfitting steady-bearing means between said parts, said cylinder being arranged to receive fluid at one end and discharge the same at the other end, a perforated attaching plate on the tapered mem ber adjacent the discharge end of the cylinder, and a flight carried by one of such parts and engaging the other to provide a passage decreasin in cross-sectional area from one end toward said attaching plate.

2. In combination, an electric motor having an armature shaft portion of hollow formation,

'air compressing means bounded by and of which said portion forms a part, said shaft having a reduced portion equipped with the commutator of the motor, one end of the hollow shaft portion having inlet means between the armature coils and commutator, and the other end of the hollow shaft portion constituting the outlet.

3. In combination, a casing having field coils interiorly thereof, a hollow shaft portion journalled in said casing having an armature ooacting with said field coils, one end of said shaft portion being an inlet and the other an outlet, said casing being perforated forwardly of the field coils, a shaft portion rigid with the hollow shaft portion having a commutator thereon forwardly of said inlet, a stator fixed to the casing and disposed in said hollow portion and perforated in line with said outlet, and coacting means between the stator and hollow shaft portion to compress fluid passing therebetween during operation.

4. In combination, a casing having interior field coils intermediate the ends thereof, a shaft comprising a hollow cylinder and a reduced portion extending therefrom, means journalling said cylinder and portion in opposite end walls of the casing, an armature on the cylinder coacting with said field coils, said cylinder at one end constituting an inlet and at the other end constituting an outlet, 2. commutator on said reduced portion forwardly of said inlet, a frusto-conical stator having a plate attached to the discharge end of the casing and perforated to discharge fluid from the cylinder, said stator being disposed in the cylinder, and flights interiorly of the cylinder engaging the stator to compress fluid during operation.

I 5. In combination, an electric motor having an armature shaft, said shaft having a portion of hollow formation, air compressing means bounded by and of which said portion forms a part, the motor having a commutator disposed on said shaft'forwardly of the hollow portion, said hollow portion adjacent one end having inlet means located between the armature of the motor and the'commutator, and the other end of the hollow shaft portion constituting the outlet.

JAMES L. JONES. 

